Damage Identification Of Transmission Tower Based On Time Series Model

After the transmission tower is put into use,it is often susceptible to corrosion due to the harsh outdoor environment.with the long service time,frequent natural disasters will inevitably cause different degrees of damage in the transmission tower.When the damage become serious,it may fall down and cause economic losses It may even cause a security accident.Therefore,it is necessary to do damage identification research on the structure of the transmission tower.The structure of the transmission tower is usually tall and complex,and it may takes a lot of resources to detect damage part by part.Therefore,an overall damage detection method is needed to identify damage to the transmission tower.Among them,most methods use the structural vibration characteristics to identify it.For the vibration parameter of a structure,the most easily measured parameter is the acceleration response sequence of the structure,that is,the sequence of acceleration changes with time.Therefore,in this paper,in order to construct the damage identification index directly,the time series model is used to model the acceleration which can avoid the loss of information in the process of extract dynamic characteristic parameters such as frequency and mode in acceleration data.This article first describes the relevant theories and the specific modeling process of the linear AR model and the nonlinear ARCH model that are widely used in the time series model,.Then the linear damage identification theory of transmission tower based on linear model and the index PCI(Pre-whitening Coefficient Index)are proposed;the nonlinear damage identification theory of transmission tower based on nonlinear ARCH model is proposed and The residual distance(RD)of the model was proposed.The theories and indicators proposed in this paper are verified by a three-layer frame structure experiment and a eight-layer frame structure numerical simulation.The results show that PCI can located the linear damage,and RD can identify the structure Non-linear damage.Finally,PCI and RD are further used for damage identification of the transmission tower,in this paper,the transmission tower is transformed into 6 layered substructures,and the acceleration of this layer is replaced by the acceleration of the node.The AR model is established to identify linear damage,and the residual is extracted to establish the ARCH model Identifying non-linear damage has also achieved relatively good results,and detected the damage location of the transmission tower.In order to show the advantages of the RD index for identifying nonlinear damage of complex structures,this paper uses SOVI,the Euclide distance index of ARCH model for nonlinear damage identification,and comparative analysis.According to the analysis,it is found that SOVI cannot be directly used for damage identification of transmission towers.The Euclide distance indicator can be used for damage identification and positioning,but it is easily interfered by structural complexity.The RD index can accurately locate the nonlinear damage of the transmission tower,and anti-interference ability is better.